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Interesting information for A2 head swap people

1946 Views 18 Replies 9 Participants Last post by  tinkerbell
First off this is my first post here and wanted to say hi. I have been doing research on both NA setups and FI setups for my K20A3 for some time now (MI4K20, you know I can't make up my mind sometimes.) and while I was leaning more and more toward turbo I found out that NA with the A3 block is actually very promising. I have a complete ported and polished Type S head, Type R intake manifold, Type S throttle body, Type R pistons and Rods, Type S ECU. I talked to Doug from Hondata today and he had this to say:

The A3 rods are weaker then the A2 - and it is revs that normally kill them. If you want to stay NA, compression is low with the A3 pistons and I would recommend aftermarket high compression pistons - such as 12:1 and rods. Combined with the Type S head and type R intake + some race headers it should fly. At high rpm, 9000 + and in racing conditions the stock pistons fail.

So it is true that the crank can handle higher revs (although i'm not going up to 9k, just staying stock A2 rev limit) I think the Type R pistons would be best, they are forged and can handle more heat and stress than the A3 pistons so NA is looking very good now.
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Thanks for the welcome man, I was going turbo but I kinda think Doug converted me per se. See, you're just like me, you've had trouble in the past figuring out what to do too. What board are you talking about? MI4? ClubRSX? I'm blocked from Clubrsx...AGAIN. And i remember trying to post on Mi-4 and people were kinda like "eh". Gonna be the first in the 757? Don't count your chickens, I can get a K24 motor for 1000 but I might stick with the k20a3 block. I've heard that the cranks on all hondas are pretty tough but it's the pistons and rods that are the weakest link(goodbye!) And I trust Doug with that kind of information. But here's the kicker, the Type S head I have is ported and polished...drool...
Thanks for the welcome nikos, I can get Type R oversized pistons for 360 shipped and forged rods for 400. No labor pay involved, my father in law got a deal going on, one of his friends owes him a favor and will do the install for free. I wasn't really planning on going to 300whp, 210-220whp is fine with me. I'm also looking into getting a k24 (CRV) engine as well and do the head swap.
nikos - I have a base rsx 5 speed.

MANNJ - What kind of rods are you using for your setup? I'm interested to find out b/c if I stick with the K20a3 block i'm going to want better rods.
almost forgot nikos, no offense, but what was the point of asking about the oil squirters when you said:

Also the k20a3 has no oil squirters and smaller water passages. For forged pistons you don;t need them, but why does the k20a R has them?

MANNJ-how much did you get your Type R crank for?
Posting once again but MANNJ, take a look at some of the dyno charts for a K24 with K20 head. The power curve is amazing and quite linear. There is no drop off in power on the dyno charts that I have seen even on a stock K24 motor and these engines (K24) are capable of revving to 8K with no problem. Slap on a JRSC onto that and your talking about in the high 280-290whp range with a linear power curve. They had a K24/K20 with JRSC in an integra and it kept up with a skyline, how's that for impressive?
Well, I'm looking into getting a K24 right now but I'm still trying to find out if the Type R pistons will fit the K24, hope they do.
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